Selective screening for Chlamydia trachomatis infection in nonurban family planning clinics in Wisconsin.

To determine the prevalence of, and identify risk factors for, Chlamydia trachomatis infection, we studied 380 women attending four Wisconsin family planning clinics in October 1985. The patients completed self-administered sexual history questionnaires, were examined by nurse clinicians and had specimens taken for direct fluorescent antibody (DFA) testing for C. trachomatis. Of 335 women with adequate specimens, 10.7 percent had positive DFA tests. Selective screening criteria were developed based on the following risk factors for C. trachomatis: Age less than 20 years and recent exposure to either a new sexual partner or a partner with more than one partner; a partner with symptoms of urethritis; a diagnosis of cervicitis; and inflammatory changes on Pap smear. Thirty-six percent of patients met one or more of these screening criteria, and the criteria had a sensitivity of 72 percent.